Multi-domain liquid crystal display device and method for fabricating the same

ABSTRACT

A multi-domain liquid crystal display (LCD) device includes a first substrate having a plurality of pixel regions each divided into at least first and second domains, a plurality of pixel electrodes each within one of the pixel regions of the first substrate, each of the pixel electrodes having a plurality of protrusions arranged along different directions within the at least first and second domains, a second substrate facing the first substrate, and a liquid crystal layer between the first and second substrates.

The present invention claims the benefit of Korean Patent ApplicationNo. P2003-43945, filed in Korea on Jun. 30, 2003, which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display (LCD) deviceand a method for fabricating an LCD device, and more particularly, to amulti-domain liquid crystal display (LCD) device and a method forfabricating an LCD device.

2. Discussion of the Related Art

As demand for various types of display devices increases various flatdisplay devices, such as liquid crystal display (LCD) devices, plasmadisplay panel (PDP) devices, electroluminescent display (ELD) devices,and vacuum fluorescent display (VFD) devices, are being developed. Someof the flat display devices are commonly used due to characteristics ofthin profile, light weight, and low power consumption, therebysubstituting cathode ray tube (CRT) devices with the LCD devices. Inaddition, mobile type LCD devices, such as displays for notebookcomputers, are being developed, and LCD devices were developed forcomputer monitors and televisions.

Despite various technical developments within the LCD device technology,enhancement of picture quality of the LCD device has been lacking. Thus,in order to use the LCD devices as general display devices, thedevelopment of LCD devices having high image quality, such as highresolution and luminance, with large-sized screens is necessary whilestill maintaining light weight, thin profile, and low power consumption.Currently, multi-domain LCD devices having at least two differentalignment directions within one pixel region have been developed toobtain LCD devices having wide viewing angles.

FIG. 1 is a schematic perspective view of an LCD device according to therelated art. In FIG. 1, an LCD device includes first and secondsubstrates 1 and 2, and a liquid crystal layer 3 formed by injectingliquid crystal between the first and second substrates 1 and 2. Morespecifically, the first substrate 1 includes a plurality of gate lines 4arranged along a first direction at fixed intervals, a plurality of datalines 5 arranged along a second direction perpendicular with the gatelines at fixed intervals to define a plurality of pixel regions P, aplurality of pixel electrodes 6 each within the pixel regions defined bythe plurality of gate and data lines, and a plurality of thin filmtransistors (TFTs) T being turned ON and OFF according to drivingsignals transmitted along the gate lines 4 for passing video signalstransmitted along the data lines to the pixel electrodes 6.

The second substrate includes a black matrix layer 7 for preventinglight leakage within regions, except the pixel regions of the firstsubstrate, and R/G/B color filter layers for producing colored light,and a common electrode 9. Although not shown, alignment layers areformed on opposing surfaces of the first and second substrates 1 and 2to align liquid crystal molecules of the liquid crystal layer 3 by arubbing method. Accordingly, the thin film transistor T includes a gateelectrode that protrudes from the gate line 4, a gate insulating layerformed along an entire surface of the first substrate 1, a sourceelectrode that protrudes from the data line 5, and a drain electrodeopposing the source electrode.

The pixel electrode 6 is formed of transparent conductive metal having ahigh transmittance of light, such as indium-tin-oxide (ITO), and theliquid crystal layer 3 is formed of Twisted Nematic (TN) mode liquidcrystal material, wherein the light oscillating along a longitudinaldirection of the liquid crystal molecules has a first refractive indexdifferent from a second refractive index of the light oscillating alonga direction vertical to the longitudinal direction of the liquid crystalmolecules, thereby creating narrow viewing angles. Accordingly, insteadof using the TN mode liquid crystal material, the liquid crystal layeris formed of Vertical Alignment (VA) mode liquid crystal material,whereby the liquid crystal molecules are aligned along differentdirections by distorting an electric field.

FIG. 2 is a cross sectional view of a unit pixel for a multi-domain LCDdevice according to the related art. In FIG. 2, upper and lowersubstrates 70 and 80 are formed to oppose each other, and a liquidcrystal layer 90 is formed between the upper and lower substrates 70 and80. In addition, projections 60 are formed along inner facing surfacesof the upper and lower substrates 70 and 80, whereinone projection 60 isformed at a center position of the inner surface of the upper substrate70, and the other projections 60 are formed on the left and right sidesof the inner surface of the lower substrate 80. If the projection 60 isformed of a material having a dielectric constant lower than adielectric constant of the liquid crystal molecule 92, the electricfield 94 (arrow direction) is formed outward to the projection 60 of theupper substrate 70. In addition, the liquid crystal molecules 92 arealigned in perpendicular to the electric field 94, whereby thearrangement of the liquid crystal molecules is divided into first andsecond domains A and B. Thus, distortion of the electric field isattenuated as the difference of the dielectric constant between theprojection 60 and the liquid crystal molecule 92 increases. Accordingly,as the projections 60 are formed of material having a dielectricconstant greater than a dielectric constant of the liquid crystalmolecule 92, it is possible to obtain a stable multi-domain LCD device.

However, the related art multi-domain LCD device has the followingdisadvantages. In the related art multi-domain LCD device, thedistortion of the electric field is formed by the projections formed onthe inner surfaces of the lower and upper substrates. As a result, theaperture ratio lowers by the occupying area of the projections on theinner surfaces of the lower and upper substrates, thereby lowering theluminance. However, since the multi-domain LCD device requires rubbingfixation or electrode structures to determine the alignment direction ofthe liquid crystal molecules, complicated manufacturing processes arerequired that increase manufacturing costs.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a multi-domain LCDdevice and a method for fabricating a multi-domain LCD device thatsubstantially obviates one or more problems due to limitations anddisadvantages of the related art.

An object of the present invention is to provide a multi-domain LCDdevice having improve aperture ratio.

Another object of the present invention is to provide a method forfabricating a multi-domain LCD device having improve aperture ratio.

Another object of the present invention is to provide a method forfabricating a multi-domain LCD device having simplified manufacturingprocesses.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned from practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the invention, as embodied and broadly described, a multi-domainliquid crystal display (LCD) device includes a first substrate having aplurality of pixel regions each divided into at least first and seconddomains, a plurality of pixel electrodes each within one of the pixelregions of the first substrate, each of the pixel electrodes having aplurality of protrusions arranged along different directions within theat least first and second domains, a second substrate facing the firstsubstrate, and a liquid crystal layer between the first and secondsubstrates.

In another aspect, a multi-domain liquid crystal display (LCD) deviceincludes a plurality of gate and data lines perpendicular to each otheron a first substrate defining a plurality of pixel regions, each of thepixel regions divided into at least first and second domains, aplurality of thin film transistors each at a crossing portion of thegate and data lines, an insulating layer within each of the pixelregions and having a plurality of first protrusions arranged alongdifferent directions in each of the first and second domains of thepixel regions, a plurality of pixel electrodes on the insulating layer,each pixel electrode having a plurality of second protrusionscorresponding to the first protrusions of the insulating layer, a secondsubstrate having a black matrix layer and a color filter layer, and aliquid crystal layer between the first and second substrates.

In another aspect, a method for fabricating a multi-domain liquidcrystal display (LCD) device includes preparing first and secondsubstrates, the first substrate having a plurality of pixel regions eachdivided into at least first and second domains, forming a plurality ofpixel electrodes in the pixel regions of the first substrate, each ofthe pixel electrodes having a plurality of protrusions arranged alongdifferent directions within one of the at least first and seconddomains, and forming a liquid crystal layer between the first and secondsubstrates.

In another aspect, a method for fabricating a multi-domain liquidcrystal display (LCD) device includes forming a plurality of gate anddata lines perpendicular to each other on a first substrate to define aplurality of pixel regions, each of the pixel regions includes at leastfirst and second domains, forming a gate insulating layer along anentire surface of the substrate including the gate lines, forming aplurality of semiconductor layers on the gate insulating layer, eachsemiconductor layer disposed above a gate electrode corresponding to thegate lines, forming source and drain electrodes on each of thesemiconductor layers, the source electrode extending from one of thedata lines, forming an insulating layer on the first substrate, etchingthe insulating layer to form a plurality of first protrusions havingfirst major-axes directions within the at least first domain and to forma plurality of second protrusions having second major-axes directionswithin the at least second domain, each of the first major-axesdirections being different from each of the second major-axesdirections, forming a plurality of pixel electrodes on the plurality offirst protrusions and the plurality of second protrusions, forming afirst alignment layer along an entire surface of the first substrateincluding the pixel electrodes, forming a black matrix layer and a colorfilter layer on a second substrate, attaching the first and secondsubstrates together, and forming a liquid crystal layer between thefirst and second substrates.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiments of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a schematic perspective view of an LCD device according to therelated art;

FIG. 2 is a cross sectional view of a unit pixel for a multi-domain LCDdevice according to the related art;

FIG. 3 is a schematic perspective view of an exemplary multi-domain LCDdevice according to the present invention;

FIG. 4A is a cross sectional view along II-II′ of FIG. 3 of liquidcrystal molecules in a multi-domain LCD device according to the presentinvention;

FIG. 4B is a cross sectional view along II-II′ of FIG. 3 of liquidcrystal molecules in a multi-domain LCD device according to the presentinvention;

FIG. 5 is a schematic perspective view of liquid crystal molecules in amulti-domain LCD device according to the present invention;

FIG. 6A is a diagram of liquid crystal molecules in a multi-domain LCDdevice according to the present invention;

FIG. 6B is a diagram of liquid crystal molecules in a multi-domain LCDdevice according to the first embodiment of the present invention;

FIG. 7A to FIG. 7E are cross sectional views of an example method offabricating a multi-domain LCD device according to the presentinvention; and

FIG. 8 is a schematic perspective view of another exemplary multi-domainLCD device according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

FIG. 3 is a perspective view schematically illustrating a multi-domainLCD device according to the first embodiment of the present invention,and FIG. 4A is a cross sectional view along II-II′ of FIG. 3. of liquidcrystal molecules in a multi-domain LCD device according to the presentinvention, and FIG. 4B is a cross sectional view along II-II′ of FIG. 3of liquid crystal molecules in a multi-domain LCD device according tothe present invention. In FIG. 4A, a state of liquid crystal moleculesis shown when an electric field is not applied in a multi-domain LCDdevice according to the present invention. In FIG. 4B, a state of liquidcrystal molecules is shown when an electric field is applied in amulti-domain LCD device according to the present invention.

In FIGS. 3, 4A, and 4B, a multi-domain LCD device may include a firstsubstrate and a second substrate 300 a and 300 b. Although notspecifically shown, but similar to the structures shown in FIG. 1, thefirst substrate 300 a may include a plurality of orthogonal gate anddata lines, which may define a plurality of pixel regions, pixelelectrodes formed in the pixel regions, and a plurality of TFTs atrespective crossing portions of the gate and data lines. The pluralityof TFTs may be turned ON/OFF according driving signals transmitted alongthe gate lines to provide video signals transmitted along the data linesto the respective pixel electrodes.

In FIGS. 3, 4A, and 4B, each of the pixel regions may be divided intofirst and second domains 301 a and 301 b. Accordingly, a pixel electrode(i.e., reflective electrode) 302 may include a plurality of protrusions309 a and 309 b, may be formed within the first and second domains 301 aand 301 b. In addition, the protrusions 309 a of the first domain 301 amay be arranged differently from the protrusions 309 b of the seconddomain 301 b.

The second substrate. 300 b may be formed to oppose the first substrate300 a. The second substrate 300 b may include a black matrix layer (notshown) for preventing light leakage within regions, except the pixelregions of the first substrate 300 a, an R/G/B color filter layer 305for producing colored light, a common electrode 304, and a secondalignment layer 303 b to provide vertical alignment of liquid crystalmolecules. Accordingly, liquid crystal layers 307 a and 307 b may beformed between the first and second substrates 300 a and 300 b.

Formation of the plurality of protrusions 309 a and 309 b within thepixel electrode 302 may first include forming an insulating layer 306 onfirst the substrate 300 a, and forming the pixel electrode 302 on in theinsulating layer 306. Accordingly, the pixel electrodes 302 may have theplurality of protrusions 309 a and 309 b formed on the insulating layer306.

Next, a first alignment layer 303 a may be formed on the pixelelectrodes 302 including the plurality of protrusions 309 a and 309 b.The plurality of protrusions 309 a and 309 b may each have an ellipticalshape having long-axis (major-axis) and short-axis (minor-axis)directions. In addition, the major-axis direction of the protrusions 309a formed within the first domain 301 a of the first substrate 300 a maycross the major-axis direction of the protrusions 309 b formed withinthe second domain 301 b of the first substrate 300 a.

In FIGS. 4A and 4B, the elliptical-shaped protrusions 309 a formedwithin the first domain 301 a may have widths corresponding to theminor-axis direction, and the elliptical-shaped protrusions 309 b formedwithin the second domain 301 b may have widths corresponding themajor-axis direction. In addition, the protrusions 309 a and 309 b maybe compactly formed at irregular intervals in order to provide diffusedreflection of incident light. However, the plurality of protrusions 309a or 309 b formed within the same domain 301 a or 301 b of one pixelregion may have their major-axes formed along one direction. Thus, anadditional alignment process for aligning liquid crystal molecules ofthe liquid crystal layers 307 a and 307 b to the first and secondalignment layers 303 a and 303 b may not be necessary.

When images are displayed by reflection of the incident light within thecolor filter layer 305 without using an additional backlight device, thepixel electrodes 302 of the first substrate 300 a may be formed of metalhaving a relatively high reflectivity. In a transmitting-type LCD deviceusing an additional backlight device, the pixel electrodes 302 of thefirst substrate 300 a may be formed of a transparent electrode material.Accordingly, the pixel electrode 302 formed of the relatively highreflectivity metal may be more advantageous than the transparentelectrode material. For example, if the pixel electrode 302 is formed ofthe relatively high reflectivity metal, the plurality of protrusions 309a and 309 b formed within the pixel electrode 302 diffuse and reflectthe incident light, thereby obtaining uniform luminance along an entiresurface of the color filter layer 305.

When a voltage is supplied to the pixel electrode 302 and the commonelectrode 304, an electric field may be formed between the pixelelectrode 302 and the common electrode 304. Accordingly, the electricfield affects the major-axes direction of the liquid crystal moleculeswithin the liquid crystal layers 307 a and 307 b, wherein the liquidcrystal layers 307 a and 307 b may be formed of negative-type liquidcrystal material. For example, when the electric field is not suppliedto the pixel electrode 302 and the common electrode 304, the liquidcrystal molecules of the liquid crystal layers 307 a and 307 b may bealigned along a direction vertical to the first and second alignmentlayers 303 a and 303 b. Conversely, when the electric field is suppliedto the pixel electrode 302 and the common electrode 304, the liquidcrystal molecules of the liquid crystal layers 307 a and 307 b may bealigned along a direction parallel to the first and second alignmentlayers 303 a and 303 b.

In FIG. 4A, when the voltage is not supplied to the pixel electrode 302and the common electrode 304, the electric field is not formed betweenthe pixel electrode 302 and the common electrode 304. Accordingly, themajor-axes of the liquid crystal molecules of the liquid crystal layers307 a and 308 b formed in the first and second domains 301 a and 301 bmay be aligned along a direction vertical to the first and secondalignment layers 303 a and 303 b. For example, the first alignment layer303 a formed within the first domain 301 of the first substrate 300 amay be formed having a shape similar to a shape of the ellipticalprotrusion 309 a formed below the first alignment layer 303 a, wherebythe first alignment layer 303 a may have the similar inclined sidesurfaces as inclined surfaces of the protrusions 309 a. Thus, themajor-axes of the liquid crystal molecules adjacent to the firstalignment layer 303 a may be arranged along the direction vertical tothe inclined surfaces of the first alignment layer 303 a due to avertical alignment restrictive force.

Along a direction from the first alignment layer 303 a to the secondalignment layer 303 b, the major-axes of the liquid crystal moleculesmay be changed to be aligned along a direction vertical to the secondalignment layer 303 b due to a vertical alignment force of the secondalignment layer 303 b. Similarly, along the direction from the firstalignment layer 303 a to the second alignment layer 303 b, themajor-axes of the liquid crystal molecules formed within the seconddomain 301 b may be aligned along a direction vertical to the secondalignment layer 303 b. Accordingly, there may be no difference in themajor-axes directions of the liquid crystal molecules between the firstand second domains 301 a and 301 b.

When the voltage is supplied to the pixel electrode 302 and the commonelectrode 304, the electric field 308 may be formed between the pixelelectrode 302 and the common electrode 304. Then, as shown in FIG. 4B,the major-axes of the liquid crystal molecules formed within the firstand second domains 301 a and 301 b may be changed to be aligned along adirection vertical to the electric field 308. For example, as shown inFIG. 5, the major-axes directions 310 a of the elliptical protrusions309 a within the first domain 301 a may cross the major-axes directions310 b of the elliptical protrusion 309 b within the second domain 301 b.Accordingly, the major-axes directions of the liquid crystal molecules311 a along the major-axes directions 310 a of the ellipticalprotrusions 309 a within the first domain 301 a may cross the major-axesdirections of the liquid crystal molecules 311 b along the major-axesdirections 310 b of the elliptical protrusions 309 b within the seconddomain 301 b. Thus, the major-axes directions of the liquid crystalmolecules adjacent to the first and second alignment layers 303 a and303 b may be effected by the vertical alignment restrictive forces whilehaving less of an effect from the electric field 308, whereby the liquidcrystal molecules adjacent to the first and second alignment layers 303a and 303 b may be maintained in an initial alignment state. As aresult, the liquid crystal molecules may be aligned differently withinthe two domains 301 and 301 b, thereby obtaining a multi-domain LCDdevice.

FIG. 6A is a diagram of liquid crystal molecules in a multi-domain LCDdevice according to the present invention;

FIG. 6B is a diagram of liquid crystal molecules in a multi-domain LCDdevice according to the present invention, wherein the multi-domain LCDdevice may be shown in FIGS. 4A and/or 4B. FIG. 6A shows lighttransmittance of liquid crystal molecules when an electric field is notapplied in a multi-domain LCD device according to the present invention.FIG. 6B shows light transmittance of liquid crystal molecules when anelectric field is applied in a multi-domain LCD device according to thepresent invention. Accordingly, FIGS. 6A and 6B demonstrate any one ofthe first and second domains 301 a and 301 b.

In FIG. 6A, before applying an electric field via pixel and commonelectrodes 302 and 304, the major-axes of the liquid crystal moleculesmay be aligned along a direction vertical to first and second substrates300 a and 300 b. Accordingly, the elliptical protrusions 309 a or 309 bmay be formed below the first alignment layer 303 a, whereby the firstalignment layer 303 may have inclined surfaces similar to inclinedsurfaces of the protrusions 309 a or 309 b. Thus, the major-axes of theliquid crystal molecules adjacent to the first alignment layer 303 a maybe vertical to the inclined surfaces of the first alignment layer 303 a,wherein the major-axes of the liquid crystal molecules corresponding toboth inclined surfaces of the first alignment layer 303 a may be formedat an angle of about ±10° to the first substrate 300 a. In addition, themajor-axes of the liquid crystal molecules corresponding to uppermost(i.e., flat) surfaces of the first alignment layer 303 a may be formedat an angle of about 90° to the first substrate 300 a. As shown in FIGS.4A and 4B, the second alignment layer 303 b of the second substrate 300b may include a flat surface having no elliptical protrusions 309 a and309 b (in FIG. 5), whereby the major-axes of the liquid crystalmolecules adjacent to the second alignment layer 303 b may be formed atan angle of about 90° to the second substrate 300 b. When no electricfield is applied, transmittance of the liquid crystal layer isapproximately 0, thereby displaying a black state.

In FIG. 6B, when applying an electric field to the liquid crystalmolecules, the major-axes of the liquid crystal molecules may be alignedvertical to the electric field direction, thereby improving lighttransmittance. Since the major-axes of the liquid crystal moleculescorresponding to the inclined surfaces of the first alignment layer 303a have a certain alignment direction with respect to the first substrate300 a, the liquid crystal molecules are inclined along a constantdirection by applying the electric field, thereby obtaining a normallight transmittance. However, the liquid crystal molecules on theuppermost (flat) surfaces of the first alignment layer 303 a may not beinclined with respect to the first substrate 300 a, for example, at anangle of about 90°. Thus, when the electric field is applied to theliquid crystal molecules, the liquid crystal molecules may beirregularly inclined. Accordingly, an area having the irregularlyinclined liquid crystal molecule may have a disclination line, whereinit is not possible to control the alignment of the liquid crystalmolecules, thereby lowering the light transmittance. However, the areahaving the disclination line is negligible as compared with normaloperation areas, so that the light transmittance may not besignificantly affected by the area having the disclination line.

FIG. 7A to FIG. 7E are cross sectional views of an example method offabricating a multi-domain LCD device according to the presentinvention. In FIG. 7A, a gate electrode (not shown) having a gateelectrode 901 may be formed on a first substrate 900 a, and a gateinsulating layer 902 may be formed along an entire surface of the firstsubstrate 900 a including the gate electrode 901. Next, a semiconductorlayer 903 may be formed on the gate insulating layer 902 above the gateelectrode 901. In addition, a data line (not shown) having source anddrain electrodes 904 a and 904 b overlapped with both sides of thesemiconductor layer 903 may be formed on the gate insulating layer 902along a direction perpendicular to the gate line. Then, an organicinsulating layer 803 for planarization and transmittance may be formedon the gate insulating layer 902 including the source and drainelectrodes 904 a and 904 b.

In FIG. 7B, a photoresist (not shown) may be deposited on the organicinsulating layer 803, and then selectively removed by photolithographicprocesses, thereby forming a plurality of protrusions within first andsecond domains 801 a and 801 b. The protrusions within the first domain801 a may have widths that are different from widths of the protrusionswithin the second domain 801 b. As shown in FIG. 3, the plurality ofprotrusions may each have an elliptical shape having major-axes andminor-axes, wherein the major-axes direction of the protrusions withinthe first domain 801 a may cross the major-axes direction of theprotrusions within the second domain 801 b. In FIGS. 7B to 7E, theplurality of protrusions within the first domain 801 a each may have awidth along the minor-axes direction, and the plurality of protrusionswithin the second domain 801 b each may have a width along themajor-axes direction.

In FIG. 7C, portions of the organic insulating layer 803 may beselectively removed above the drain electrode 904 b, thereby forming acontact hole. Then, a pixel electrode 804 may be formed on the organicinsulating layer 803 of the pixel region to be connected to the drainelectrode 904 b through the contact hole. Since the organic insulatinglayer 803 may include the plurality of protrusions, the pixel electrodes804 may be formed to each have shapes corresponding to the plurality ofprotrusions. The pixel electrode 804 may be formed of a metal materialhaving high reflectivity, or of a transparent conductive material, suchindium-tin-oxide (ITO).

In FIG. 7D, a first alignment layer 805 a may be formed along an entire.surface of the first substrate 900 a including the pixel electrode 804.The first alignment layer 805 a may be formed using one of a spinning,spraying, dipping, or printing methods, and may be formed of polyamideor polyimide group compound materials, such as polyvinylalcohol (PVA),polyamic acid material, or may be formed of photoreactive materials,such as polyvinylcinnamate (PVCN), polysiloxanecinnamate (PSCN), orcellulosecinnamate (CelCN). The first alignment layer 805 a may beformed o provide a vertical alignment of the liquid crystal moleculeswithin the liquid crystal layer, wherein additional alignment processesmay not be necessary.

In FIG. 7E, a black matrix layer 906 may be formed on a second substrate900 b to prevent light leakage on portions, except for the pixelregions, and a color filter layer 907 may be formed to produce coloredlight within the pixel regions. In addition, a common electrode 908 maybe formed along an entire surface of the second substrate 900 bincluding the color filter layer 907, and a second alignment layer 805 bmay be formed on the common electrode 908. The second alignment layer805 b may be formed of the same material as the first alignment layer805 a, wherein the second alignment layer 805 b may not requireadditional alignment processes.

Although not shown, a plurality of spacers and sealant material may beformed on one or both of the first and/or second substrate 900 a and/or900 b, and the first and second substrates 900 a and 900 b may be bondedto each other. Then, the liquid crystal layer 806 having the liquidcrystal molecules aligned along the vertical direction may be formedbetween the first and second substrates 900 a and 900 b. When an inletis formed within the sealant, the first and second substrates 900 a and900 b may be bonded to each other by the sealant while being maintainedin a vacuum state. Accordingly, the inlet may be dipped into a vesselhaving liquid crystal material, whereby the liquid crystal may beinjected between the first and second substrates 900 a and 900 b byosmotic action, thereby forming the liquid crystal layer 806.Alternatively, the liquid crystal material may dispersed on one of thefirst and second substrates 900 a and 900 b, and then the first andsecond substrates 900 a and 900 b may be bonded to each other.

FIG. 8 is a schematic perspective view of another exemplary multi-domainLCD device according to the present invention. In FIG. 8, one pixelregion may be divided into first, second, third, and fourth domains 701a, 701 b, 701 c, and 701 d, and a plurality of elliptical protrusions800 a, 800 b, 800 c, and 800 d may be formed within the respectivefirst, second, third, and fourth domains 701 a, 701 b, 701 c, and 701 d.Accordingly, the major axes directions of the plurality of protrusions800 a, 800 b, 800 c, and 800 d may be different within each of thefirst, second, third, and fourth domains 701 a, 701 b, 701 c, and 701 d,thereby obtaining a multi-domain LCD device having at least fourdomains. Of course, an LCD device according to the present invention maybe provided having an increased number of domains, such as 6, 8, 10, . ..

The elliptical protrusions 800 a of the first domain 701 a may havemajor-axes directions similar to major-axes directions of the ellipticalprotrusions 800 c of the third domain 701 c. Similarly, the ellipticalprotrusions 800 b may have major-axes directions similar to major-axesdirections of the elliptical protrusions 800 d of the fourth domain 701d. In addition, the major-axes directions of the protrusions 800 a and800 c within the first or third domain 701 a or 701 c may have adirection vertical to the major-axes directions of the protrusions 800 band 800 d within the second or fourth domain 701 b or 701 d. Moreover,the major-axes directions within each of the first, second, third, andfourth domains 701 a, 701 b, 701 c, and 701 d may be different.

According to the present invention, A plurality of protrusions of apixel electrode may be aligned along different directions withindifferent domains of a pixel region to obtain a multi-domain LCD devicehaving high aperture ratio and without requiring additional structures.In addition, a simplified fabrication process may be achieved, therebydecreasing manufacturing costs. Furthermore, a reflective- ortransmitting-type multi-domain LCD device may be fabricated according tomaterials of a pixel electrode, thereby improving efficiency.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the multi-domain liquidcrystal display device and method for fabricating a multi-domain liquidcrystal display device of the present invention without departing fromthe spirit or scope of the invention. Thus, it is intended that thepresent invention cover the modifications and variations of thisinvention provided they come within the scope of the appended claims andtheir equivalents.

1-12. (canceled) 13: A multi-domain liquid crystal display (LCD) device,comprising: a plurality of gate and data lines perpendicular to eachother on a first substrate defining a plurality of pixel regions, eachof the pixel regions divided into at least first and second domains,wherein the first and second domains are symmetric with respect to avirtual line which divides the pixel region into the first and seconddomains; a plurality of thin film transistors each at a crossing portionof the gate and data lines; an insulating layer within each of the pixelregions and having a plurality of first protrusions arranged alongdifferent directions in each of the first and second domains of thepixel regions, wherein each of the protrusions is formed as anelliptical shape having major-axes and minor-axes, and the major-axes ofthe protrusions within the first domain are disposed along a directionvertical to a direction of the major-axes of the protrusions within thesecond domain; a plurality of pixel electrodes on the insulating layer,each pixel electrode having a plurality of second protrusionscorresponding to the first protrusions of the insulating layer; a secondsubstrate having a black matrix layer and a color filter layer; and aliquid crystal layer between the first and second substrates. 14-15.(canceled) 16: The device according to claim 13, further comprising afirst alignment layer on the pixel electrodes and a second alignmentlayer on the second substrate. 17: The device according to claim 13,wherein each of the pixel electrodes is formed of a relatively highreflectivity metal material. 18: The device according to claim 13,wherein each of the pixel electrodes is formed of a transparentconductive material. 19: The device according to claim 13, wherein theliquid crystal layer is formed of vertical-alignment type liquid crystalmaterial. 20-36. (canceled) 37: A method for fabricating a multi-domainliquid crystal display (LCD) device, comprising the steps of: forming aplurality of gate and data lines perpendicular to each other on a firstsubstrate to define a plurality of pixel regions, each of the pixelregions includes at least first and second domains, wherein the firstand second domains are symmetric with respect to a virtual line whichdivides the pixel region into the first and second domains; forming agate insulating layer along an entire surface of the substrate includingthe gate lines; forming a plurality of semiconductor layers on the gateinsulating layer, each semiconductor layer disposed above a gateelectrode corresponding to the gate lines; forming source and drainelectrodes on each of the semiconductor layers, the source electrodeextending from one of the data lines; forming an insulating layer on thefirst substrate; etching the insulating layer to form a plurality offirst protrusions and to form a plurality of second protrusions, whereineach of the first and second protrusions is formed as an ellipticalshape having major-axes and minor-axes, and the major-axes of the firstprotrusions within the first domain are disposed along a directionvertical to a direction of the major-axes of the second protrusionswithin the second domain; forming a plurality of pixel electrodes on theplurality of first protrusions and the plurality of second protrusions;forming a first alignment layer along an entire surface of the firstsubstrate including the pixel electrodes; forming a black matrix layerand a color filter layer on a second substrate; attaching the first andsecond substrates together; and forming a liquid crystal layer betweenthe first and second substrates. 38-45. (canceled)